Fluid-pressure-maintaining system.



P. H. DUKESMITH.

FLUID PRESSURE MAINTAINING SYSTEM.

APPLICATION FILED NOV. 27, 1912.

1,081,526. Patented Dec. 16, 1913.

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P. H. DUKESMITH.

FLUID PRESSURE MAINTAINING SYSTEM. APPLICATION FILED NOV. 27, 1912.

1,081,526. Patent ed Dec. 16, 1913 2 SHEETSSHEBT 2.

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FRANK H. DUKESMITI-I, OF BUFFALO, NEW YORK, ASSIGNOR, BY DIRECT ANDMESNE ASSIGNMENTS, TO THE UNITED STATES AIR BRAKE CORPORATION, OFBUFFALO, NEW YORK, A CORPORATION OF NEW YORK.

FLUID-PRESSURE-IIAINTAININ G SYSTEM.

menses.

Application filed November 27, 1912.

To all whom it may concern:

Be it known that I, FRANK H. DUKE- SMITH, a citizen of the UnitedStates, residing at Buffalo, in the county of Erie and State of NewYork, have invented certain new and useful Improvements in Fluid-PressureMaintaining Systems, Particularly for Use in Connection withRailway-Air- Brake Cylinders.

The following I declare to be a full, clear, and exact description of myinvention, such as will enable others skilled in the art to which itappertains to make and use the same, reference being had to theaccompanying drawings, and to figures of reference marked thereon, whichform part of this specification.

Like figures refer to like parts.

My invention relates to a system of valves and other devices adapted tooperate automatically to rebuild pressure in a brake cylinder or otherdevice when leakage occurs to reduce pressure.

The object of my invention is to provide a system of means forautomatically releasing air or other fluid under pressure from itssource int-o channels connected with a brake cylinder or other device torestore pressure lost by leakage.

A further object is to automatically shut off the source of pressureduring exhaust from the said cylinder or other device and prevent thecompressed fluid from wasting at that time.

My invention is actuated by slight changes from the full active pressureinitially used in each instance of setting the brakes, regardless ofwhat that pressure may be. Among other things, I provide a valvemechanism having two chambers with a flexible wall between them. One ofthe chambers I designate as the variable pressure chamber, which beingin open communication with the brake cylinders at all times has withinit the same pressure as obtains in said cylinders. The other chamber Istyle the control chamber wherein the air under the said full activeinitial pressure is stored and held there by a check valve. As soon asthe pressure in the variable chamber becomes reduced, the storedpressure in the control chamber distends the flexible wall and thusautomatically furnishes a forcible means for openinga valve connectedSpecification of Letters Patent.

Patented Dec. 16, 1913.

Serial No. 733,856.

with a source of fluid pressure, releasing the same to rebuild thepressure lost by leakage.

Details of arrangement and construction of the means employed inconnection with the two chambers just described are illustrated in theaccompanying drawings, showing two modifications of my invention asemployed in connection with an ordinary railway air brake equipment.Following a detailed description of the parts illustrated, theoperations of the same, for various conditions of pressure in the brakecylinder, are explained and what I claim is set forth.

Figure 1 is a diagrammatic illustration of an ordinary railway air brakeequipment in connection with one form of my system of valves shown insection as a compound valve. Fig. 2, is similar to Fig. 1, except thatit shows a modified form of my system of valves in connection with saidequipment. Fig. 3, is a top plan of an engineers automatic brake valvewith attachments including an exhaust valve. Fig. 4; is a horizontalsection of the compound valve taken on the line XX of Fig. 1.

In Fig. 1, the principal features of an ordinary railway air brakeequipment are shown as follows :1 is an engineers automatic brake valveconnected by pipe 2 to the main reservoir 3, to which is connected apump 4. Also connected with the valve 1, is the pipe 5, in connectionwith the train pipe 6. A branch pipe 7 connects the triple valve 8 withthe train pipe 6. Connected with the triple valve 8 by the pipe 8 is theauxiliary reservoir 9. 8 is an exhaust pipe on the triple valve 8. Brakecylinders 10 and 11, by means of the pipe 12, are connected with thetriple valve 8. A I 13 is in the line of pipe 12. Interposed incontinuous connection between the auxiliary reservoir 9 and the I 13,are the pipe 14, the check valve 15, having a hinged disk 16, adapted toclose a port 16 a supplemental reservoir 17, the

.pipe 18, the compound valve 19, and the pipe 20. In the sectional viewof the valve 19, under the cap 21 is a control pressure chamber 22,separated by a diaphragm 23 from a variable pressure chamber 24:. Rings23 and 23 hold the diaphragm 23 in position. Depending from thediaphragm 23 is the cone 25, held thereon by the disk 25 and the nut 25.lVithin the .vided through the piston disk 37.

lower end of the cone 25 is loosely fitted a stem 26, which is connectedwith a disk 27. This disk is shown closed against a valve seat 28, beingnormally held in this position by the spring 29, through which passesthe stem 30. The stem 30 is adapted tov reciprocate in the hole 31 andwhen down it closes communication with the passage 32. Leading from thechamber 33 to the chamber 34 is the passage 35. Below the chamber 33 isa valve seat 36, the port of which is adapt ed to be closed by a pistondisk 37, but is held normally open by the spring 38; the disk 37 beingadapted to reciprocate as a piston within the cylindrical portion 39 ofthe valve 19. A small passage 40 is pro- The lower end of the valve 19.is closed by the cap 41, in the center of which is a passage 42 incommunication with the piping 18. Through the raised portion of the cap41, in contact with the piston disk 37, is a hole 43. In the upper lefthand corner of the compound valve 19 is a check valve having a chamber44 in which is a disk 45, adapted to close a port in the valve seat 59,which is a continuation of passage 46, which passage is in communicationwith the variable pressure chamber 24. The stem 48 of the disk 45 isadapted for reciprocation within the cap 47. A spring 49 within the cap47 holds the check valve normally closed. In the chime of the cap 21 areholes 50, 51, which form with the passage 52, free communication betweenthe chambers 44 and 22. In the upper right hand corner of the chamber 24is a differential check valve having a valve seat 53, through which is apassage 54 communicating with the chamber 22.

Adapted to close the port in the valve seat 53 is the disk 55 on thestem 56, which is adapted to reciprocate within the cap 57. A spring 58holds the valve normally closed. The area of the valve seat 53 incontact with the disk 55 is several times larger than the area of theport it closes. In this Fig. 1, the valve 1 has a handle 61 and a topflange 76 correspondingly numbered to what 'is shown in Figs. 2 and 3.

In Fig. 2, a similar set of valves, reservoirs and connections to thosedescribed for Fig. 1, is illustrated and like parts are respectivelynumbered. The compound valve 19 is similar to valve 19 with theexception that it has no diii'erential check valve. The engineersautomatic brake valve 1, shown in this figure, has a handle 61. Abracket 62 is attached to the casing of the valve 1*. Fulcrumed in thebracket- 62 is the lever 63 having a free beveled end 63 adapted toengage, at times, the handle 61. Pivoted to the lever 63 is a yoke 64.Depending from the yoke 64 is a stem 65 of an exhaust valve 60 shown insection. The stem 65 passes down through a cap 66, then through achamber 67 and a valve seat 68 into a chamber 69. A disk 70, adapted toclose, a port in the seat 68, is fixed upon the stem 65. A spring 71 isadapted to hold this valve 60 normally closed. The lower end of the stem65 fits into a hole 72 in the easing of this check valve. A pipe 73connects the passage 21' of the valve 19 with a passage 74 leading intothe chamber 69. A passage 75 in the cap 66 affords an outlet from thechamber 67 to the atmosphere.

In the top plan of the valves 1 and 60'.

illustrated in Fig. 3, the lever 63 is shown with a curved portionconcentric with the turning point of the lever 61.. In the top flange 76are five notches 77, 78, 79, 80 and 81, each of which respectivelylocates the handle 61 in one of the five positions of the engineersautomatic brake valve. It will be seen from this Fig. 3, that in onlytwo positions, that for notch 81 and that for notch 80, where the handleis shown in dotted position 61*, can the lever 63 be engaged anddepressed to open the valve 60.

In Fig. 4, the position of the hole 40 in the piston disk 37 and the,hole 43 underneath the disk 37 are shown.

In the form of my invention shown in Fig. 1, compressed air from theauxiliary reservoir 9 is free to pass the port- 16 of the check valve15, raising the disk 16 and passing into the supplemental reservoir 17,charges the same.

Instead of connecting the check valve 15 with the reservoir 9,connection might be made direct with the train pipe 6, as the source offluid pressure. In either case the check valve 15 will prevent the backflow from the reservoir 17. Air under pressure from any other source, asthe main reservoir 3 or the pump 4, might be passed through the checkvalve 15. instead of from the auX- iliary reservoir 9.

Air from the supplemental reservoir 17 is free to pass through the pipe18 into the passage 42, between the cap 41, and the piston disk 37 andthence through the hole 43 into the passage 40 of the piston disk 37 andover the top of the same into the port 36, the chamber 33, the passage35 and into the chamber 34, at the same time air is passing through thepassage 32 into chamber 33 the port 36 being normally open, on accountof the piston disk 37 being held away from it by the spring 38, and theport in valve seat 28 being normally closed by the spring pressed disk27. The hole 40 is made comparatively small, being only large enough toallow sutlicient air to pass it to compensate for ordinary leakage inthe brake cylinders.

The variable pressure chamber 24 being pressure used in setting thebrakes passes through the channel 46 raising the spring pressed disk 45,enters the chamber 44, the channel 52, the holes 50 and 51 and thechamber 22. In communication with this chamber 22 is the channel 54,closed by the spring pressed disk 55, but in as much as the disk 55 isexposed freely to the pressure in the chamber 24, it will remain closedduring the equalization of pressure in the two chambers 22 and 24, atthe time of the presence of said full active initial pressure. Onaccount of the equalization of pressure on both sides of the flexiblediaphragm 23 there will be no movement of the same and the disk 27 willremain normally against its seat 28. Air at the said initial pressurewill now remain stored in control chamber 22 until released through thevalve seat 53. The area of the seat 53 being large compared with theport therein of the channel 54, a considerable reduction in pressure inthe chamber 24 will be necessary to effect the opening of this valve torelease the pressure in the chamber 22. Therefore for slight reductionsof pressure in the chamber 24, there will remain the said initialpressure to force the diaphragm 23 down when the difference in pressureon the two sides of the same is sufficient to force the disk 27 off itsseat and allow air under pressure to rebuild that which had becomereduced in the chamber 24, and when this pressure has been restored, thediaphragm 23 will, on account of the condition of equalized pressure ornearly so, in the two chambers 24 and 22, take its normal position andthe disk 27 will again become normally seated, closing ofi the air fromthe supplemental reservoir 17. In thus restoring pressure within thechamber 24, air is supplied to the brake cylinders 10 and 11 to rebuildthat lost by leakage. Should the brakes be released and the cylindersexhausted during the automatic operation just described, in restoringthe leakage, the sudden drop in pressure while the disk 27 is off itsseat will make a considerable diiference in pressure on the upper andlower sides of the piston disk 37, causing it to be forced to its seat36, and close the port therein. The stem 30 being down, no air can passinto chamber 33 through the passage 32 and the hole 31, but should thedisk 27 become normally seated, these passage ways will become connectedupon the raising of the stem 30 and the pressure will become equalizedon opposite sides of the piston disk '37, which will leave the spring 38free to operate and force the disk 37 off its seat 36 causing the porttherein to become normally open. Also due to the sudden drop in pressurein the chamber 24 during exhaust of the brake cylinders, the initialpressure in the chamber 22 will push the disk 55 01% its seat andexhaust through the channel 54 and release the pressure upon thediaphragm 23, which would otherwise hold the disk 27 off its seat. Afterexhaust from the cylinders has taken place the various valves justdescribed are again in normal position ready to be again operated andperform their functions when the brakes are again set by full activepressure, and the chamber 22 again becomes charged in the mannerpreviously described.

While the supply valve with the disk 27, the check valve with the disk45, the differential check valve with the disk 55 and the stop valvewith the piston disk 37, with certain connecting channels justdescribed, 5; have been shown in section as a compound valve within onecasing for convenience, each of said valves might be isolated except forchannel connections formed of piping and all might be correlated in thesame relation apart from a common casing and be operative in the waydescribed above.

In the system shown in Fig. 2 the compound valve 19 is in all parts andfunctions correlated like those described above for compound valve 19,except that the differential check valve is not used to release the airfrom the chamber 22. In this form of my invention I provide a checkvalve 60, which when open, exhausts the air in the 9 chamber 22 throughthe passage 21, the pipe 7 3, the passage 74, the chamber 69, thechamber 67 and the hole 75 to the atmosphere. This exhaust can takeplace pending either of the two positions of the engineers automaticbrake valve 1 known as the full release and the running posit-ions. Ineither of these positions the handle 61 depresses the lever 63 causingthe yoke 64 to force down the stem 65 and push the disk off its seat,opening the valve to the atmosphere.

In Fig. 3 the handle 61 is drawn in full lines over the notch 81 andrepresents full release position of said handle. The dotted position at61 shows the handle in running position over notch 80. As the handle 61is moved in succession over the notches 77, 78, 7 9 to it only engagesthe beveled end 63 of the lever 63 as it passes M5 into position 61 Forthe positions of the handle over notch 77 known as emergency Jill.)

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a 3 )lication over notch 7 3 known as service application, and that overnotch 79 known as lap position the handle 61 is 1120 free from the lever63 and the. valve 60, by means of the spring 71, remains normallyclosed. Hence during the lap, service, or emergency positions of thehandle any initial pressure stored in the control chamber 22 is therereserved for action upon the diaphragm 23, as described above inconnection with Fig. 2, but when the brakes are released by bringing thehandle 61 to running or release position the lever 63 is lLi-J depressedopening valve 60, releasing the pressure in the chamber 22.

Releasing means operated in. connection with the triple valve 8 duringexhaust from the brake cylinders might be substituted for either ofthose, described in connection with Figs. 1 and 2 for releasing thepressure in the control chamber 22 during said exhaust.

Having described my invention I claim 1. A pressure maintaining systemof devices in combination with an air brake cylinder and means forsupplying fluid pressure, said system of devices consisting of, a valvemechanism having chamber connected with said cylinder and a pressurecontrol chamber separated from said variable pressure chamber by amovable wall, there being a passage connecting said chambers, a. checkvalve in said passage adapted to permit air to flow through said passageinto said control chamber, pressure releasing means connected with saidcontrol chamber, a supply valve adapted to be operated by said movablewall, a stop valve between said supply valve and said means forsupplying fluid pressure, said stopv valve having a port in its seat anda disk adapted to close said port, there being a restricted openingthrough said disk, out of alinement with said port, means aftordingchannels from said stop valve to said supply valve apart from the portsin the seats of said valves, and means. adapted to close, said channelsduring the opening of said supply valve.

2', In, combination with an air brake cylinder and means for supplyingfluid pressure, a. pressure maintaining system of devices comprising asupplemental reservoir, a check valve between said means for supplyingfiuid pressure and said supplemental reservoir, a valve mechanism havingtwo chambers separated by a movable-wall, one of said chambers beingconnected with said cylinder, the other chamber being a control chamber,there being a passage connecting said chambers, a check valve in saidpassage adapted to permit air to pass into said control chamber, asupply valve adapted. to be operated by said movable wall, pressurereleasing means connected with said control chamber, means affordingconnections between said means for supplying pressure and said supplyvalve, and interposed means in said connections adapted to pass smallquantities of air to replenish leakage in said cylinder and to shut offsaid air to said supply valve upon a sudden diminution of pressure insaid cylinder.

3. In co ination with an air brake cylinder and means for supplyingfluid pressure, a, pressure maintaining system of devices comprising' asupplemental reservoir, a check valve between said means for supplyingfiuid pressure and said supplemental a variable pressurereservoir, avalve mechanism having two chambers separated by a movable wall, one ofsaid chambers being connected with said cylinder, the other chamberbeing a control chamber, there being a passage connecting said chambers,a check valve in said passage adapted to permit air topass into saidcontrol chamber a supply valve adapted to be operated by said movablewall, pressure releasing means connected with said control chamber,means affording connections between said means for supplying pressureand said supply valve, interposed means in said connections adapted topass small quantities of air to replenish leakage in said cylinder andto shut oil said air to said supply valve upon a sudden diminution of.pressure in. said cylinder,- and means for equalizing pressure withinsaid connections on either side 01": said interposed means upon theclosure of said supply valve.

4. A pressure maintaining system of devices in combination with an airbrake cylinder and means for supplying fluid pressure, said system ofdevices consisting of a valve mechanism having a variable pres surechamber connected with said cylinder and a pressure control chamberseparated from said variable pressure chamber by a movable wall, therebeing a passage connectin-g said chambers, a check valve in said passageadapted to ermit air to flow through said passage into said controlchamber, a manually controlled release valve connected with said controlchamber, a supply valve adapted to be operated by said movable wall, astop valve between said supply valve and said means for supplying flu-idpressure, said step valve having a port in its. seat and a dish adaptedto close said port, there being a restricted: opening through said dish,out of alinement with said port, means affording channels from said stopvalve to said sup-ply valve apart from the ports in the seats of saidvalve, and means adapted to close said channels during the opening ofsaid supply valve.

5. A pressure maintaining system of devices in combination with an airbrake cylinder, an engineers automatic brakev valve, and means forsupplying fluid pressure, saidsystem of devices consisting of, a valvemechanism having a variable pressure chamber connected with saidcylinder and a pressure control chamber separated from said variablepressure chamber by a movable wall, there being a passage connectingsaid chambers, a check valve in said passage adapted to permit air toflow through said passage into said control chamber, pressure releasingmeans connected with said control chamber, said a stop valve betweensaid supply valve and said means for supplying fluid pressure, said stopvalve having a port in its seat and a disk adapted to close said port,there being a restricted opening through said disk, out of alinementwith said port, means affording channels from said stop valve to saidsupply valve apart from the port in the seat of said valve, and meansadapted to close said channels during the said opening of said supplyvalve.

6. A pressure maintaining system of devices in combination with an airbrake cylinder, and means for supplying fluid pressure, said system ofdevices consisting of a valve mechanism having a variable pressurechamber connected with said cylinder and a pressure control chamberseparated from said variable pressure chamber by a movable Wall, therebeing a passage connecting said chambers, a check valve in said passageadapted to permit air to flow through said Copies of this patent may beobtained for passage into said control chamber, pressure releasing meansconnected With said control chamber, said releasing means being adaptedto be normally closed during the restoration of pressure in saidcylinder, a supply valve adapted to be operated by said movable Wall, astop valve between said supply valve and said means for supplying fluidpressure, said stop valve having a port in its seat and a disk adaptedto close said port, there being a restricted opening through said disk,out of alinement with said port, means affording channels from said stopvalve to said supply valve apart from the ports in the seats of saidvalves, and means adapted to close said channels during the opening ofsaid supply valve.

FRANK H. DUKESMITH.

WVitnesses:

J AOOB WELOHER, J. EDWARD THEBAUD.

five cents each, by addressing the Commissioner of Patents, Washington,D. G.

